Enantioselective Catalysis of an Anionic Oxy‐Cope Rearrangement Enabled by Synergistic Ion Binding

Charge‐accelerated rearrangements present interesting challenges to enantioselective catalysis, due in large part to the competing requirements for maximizing reactivity (ion‐pair separation) and stereochemical communication. Herein, we describe application of a synergistic ion‐binding strategy to catalyze the anionic oxy‐Cope rearrangement of a symmetric bis‐styrenyl allyl alcohol in up to 75 : 25 e.r. Structure‐reactivity‐selectivity relationship studies, including linear free‐energy‐relationship analyses, with bifunctional urea catalysts indicate that H‐bonding and cation‐binding interactions act cooperatively to promote the chemo‐ and enantioselective [3,3]‐rearrangement. Implications for catalyst designs applicable to other transformations involving oxyanionic intermediates are discussed.